SAA induces suppressive neutrophils via the TLR2-mediated signaling pathway to promote progression of breast cancer

SAA1 Protein: A Potential Biomarker for Acute Myeloid Leukemia

Background/Objectives: Despite its heterogeneity and diagnostic challenges, acute myeloid leukemia (AML) originates from stem cell transformation and alterations in the hematopoietic niche (HN) could be related to leukemic transformation. Therefore, the aim of this study was to evaluate the protein profile of HN from AML patients and compare it with the profile of healthy donors (HDs). Methods: A proteomic analysis was conducted to identify differentially expressed (DE) proteins in BM plasma from AML patients and HD. In silico analysis was performed to identify biological processes and signaling pathways involved. Additionally, ELISA confirmed the expression of the DE protein of interest in BM plasma samples. Results: Proteomic analysis revealed alterations in the plasma profiles of AML patients and 36 DE proteins were found. Among then, we highlight C8G, CFB, SAA1, SERPINA3 and SERPINC1, which are related to inflammatory response process. Thus, considering the role of the secreted protein SAA1 in the inflammatory context and that it is described as a potential biomarker in several tumors, we selected SAA1 for ELISA confirmation. The results corroborated our findings, indicating that increased expression of SAA1 could be related to AML. Our results also revealed that SAA1 can stimulate immune signaling through NF-kappa-B activation. Conclusions: These findings position SAA1 as a promising biomarker for AML diagnosis, offering a potential tool for more accurate identification of the disease. Nevertheless, further studies are needed to understand the relationship of SAA1 with the leukemic transformation process in AML and its potential clinical use.

Recent Advances in Studies of Serum Amyloid A: Implications in Inflammation, Immunity and Tumor Metastasis

Research on serum amyloid A (SAA) has seen major advancement in recent years with combined approaches of structural analysis and genetically altered mice. Initially identified as an acute-phase reactant, SAA is now recognized as a major player in host defense, inflammation, lipid metabolism and tumor metastasis. SAA binding and the neutralization of LPS attenuate sepsis in mouse models. SAA also displays immunomodulatory functions in Th17 differentiation and macrophage polarization, contributing to a pro-metastatic tumor microenvironment. In spite of the progress, the regulatory mechanisms for these diverse functions of SAA remain unclear. This review provides a brief summary of recent advances in SAA research on immunity, inflammation, tumor microenvironment and in vivo models.

Resolution of chronic inflammation and cancer

Chronic inflammation poses challenges to effective cancer treatment. Although anti-inflammatory therapies have shown short-term benefits, their long-term implications may be unfavorable because they fail to initiate the necessary inflammatory responses. Recent research underscores the promise of specialized pro-resolving mediators, which play a role in modulating the cancer microenvironment by promoting the resolution of initiated inflammatory processes and restoring tissue hemostasis. This review addresses current insights into how inflammation contributes to cancer pathogenesis and explores recent strategies to resolve inflammation associated with cancer.

Effects of T2DM on cancer progression: pivotal precipitating factors and underlying mechanisms

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder affecting people worldwide. It is characterized by several key features, including hyperinsulinemia, hyperglycemia, hyperlipidemia, and dysbiosis. Epidemiologic studies have shown that T2DM is closely associated with the development and progression of cancer. T2DM-related hyperinsulinemia, hyperglycemia, and hyperlipidemia contribute to cancer progression through complex signaling pathways. These factors increase drug resistance, apoptosis resistance, and the migration, invasion, and proliferation of cancer cells. Here, we will focus on the role of hyperinsulinemia, hyperglycemia, and hyperlipidemia associated with T2DM in cancer development. Additionally, we will elucidate the potential molecular mechanisms underlying their effects on cancer progression. We aim to identify potential therapeutic targets for T2DM-related malignancies and explore relevant directions for future investigation.

Integrative proteome analysis of bone marrow interstitial fluid and serum reveals candidate signature for acute myeloid leukemia

Acute myeloid leukemia (AML) is an aggressive form of blood cancer and clinically highly heterogeneous characterized by the accumulation of clonally proliferative immature precursors of myeloid lineage leading to bone marrow failure. Although, the current diagnostic methods for AML consist of cytogenetic and molecular assessment, there is a need for new markers that can serve as useful candidates in diagnosis, prognosis and understanding the pathophysiology of the disease. This study involves the investigation of alterations in the bone marrow interstitial fluid and serum proteome of AML patients compared to controls using label-free quantitative proteomic approach. A total of 201 differentially abundant proteins were identified in AML BMIF, while in the case of serum 123 differentially abundant proteins were identified. The bioinformatics analysis performed using IPA revealed several altered pathways including FAK signalling, IL-12 signalling and production of macrophages etc. Verification experiments were performed in a fresh independent cohort of samples using MRM assays led to the identification of a panel of three proteins viz., PPBP, APOH, ENOA which were further validated in a new cohort of serum samples by ELISA. The three-protein panel could be helpful in the diagnosis, prognosis and understanding of the pathophysiology of AML in the future. BIOLOGICAL SIGNIFICANCE: Acute Myeloid Leukemia (AML) is a type haematological malignancy which constitute one third of total leukemias and it is the most common acute leukemia in adults. In the current clinical practice, the evaluation of diagnosis and progression of AML is largely based on morphologic, immunophenotypic, cytogenetic and molecular assessment. There is a need for new markers/signatures which can serve as useful candidates in diagnosis and prognosis. The present study aims to identify and validate candidate biosignature for AML which can be useful in diagnosis, prognosis and understand the pathophysiology of the disease. Here, we identified 201 altered proteins in AML BMIF and 123 in serum. Among these altered proteins, a set of three proteins viz., pro-platelet basic protein (CXCL7), enolase 1 (ENO1) and beta-2-glycoprotein 1 (APOH) were significantly increased in AML BMIF and serum suggest that this panel of proteins could help in future AML disease management and thereby improving the survival expectancy of AML patients.

SAA1-dependent reprogramming of adipocytes by tumor cells is associated with triple negative breast cancer aggressiveness

Triple negative breast cancers (TNBC) are characterized by a poor prognosis and a lack of targeted treatments. Their progression depends on tumor cell intrinsic factors, the tumor microenvironment and host characteristics. Although adipocytes, the primary stromal cells of the breast, have been determined to be plastic in physiology and cancer, the tumor-derived molecular mediators of tumor-adipocyte crosstalk have not been identified yet. In this study, we report that the crosstalk between TNBC cells and adipocytes in vitro beyond adipocyte dedifferentiation, induces a unique transcriptional profile that is characterized by inflammation and pathways that are related to interaction with the tumor microenvironment. Accordingly, increased cancer stem-like features and recruitment of pro-tumorigenic immune cells are induced by this crosstalk through CXCL5 and IL-8 production. We identified serum amyloid A1 (SAA1) as a regulator of the adipocyte reprogramming through CD36 and P2XR7 signaling. In human TNBC, SAA1 expression was associated with cancer-associated adipocyte infiltration, inflammation, stimulated lipolysis, stem-like properties, and a distinct tumor immune microenvironment. Our findings constitute evidence that the interaction between tumor cells and adipocytes through the release of SAA1 is relevant to the aggressiveness of TNBC.

Toll-like receptors in health and disease

Toll-like receptors (TLRs) are inflammatory triggers and belong to a family of pattern recognition receptors (PRRs) that are central to the regulation of host protective adaptive immune responses. Activation of TLRs in innate immune myeloid cells directs lymphocytes to produce the most appropriate effector responses to eliminate infection and maintain homeostasis of the body's internal environment. Inappropriate TLR stimulation can lead to the development of general autoimmune diseases as well as chronic and acute inflammation, and even cancer. Therefore, TLRs are expected to be targets for therapeutic treatment of inflammation-related diseases, autoimmune diseases, microbial infections, and human cancers. This review summarizes the recent discoveries in the molecular and structural biology of TLRs. The role of different TLR signaling pathways in inflammatory diseases, autoimmune diseases such as diabetes, cardiovascular diseases, respiratory diseases, digestive diseases, and even cancers (oral, gastric, breast, colorectal) is highlighted and summarizes new drugs and related clinical treatments in clinical trials, providing an overview of the potential and prospects of TLRs for the treatment of TLR-related diseases.

High-Throughput Transcriptomics of Nontumorigenic Breast Cells Exposed to Environmentally Relevant Chemicals

BACKGROUND

There is a suite of chemicals, including metals, pesticides, and personal care product compounds, which are commonly detected at high levels in US Center for Disease Control's National Health and Nutrition Examination Survey (NHANES) chemical biomarker screens. Whether these chemicals influence development of breast cancer is not well understood.

OBJECTIVES

The objectives were to perform an unbiased concentration-dependent assessment of these chemicals, to quantify differences in cancer-specific genes and pathways, to describe if these differences occur at human population-relevant concentrations, and to specifically test for differences in markers of stemness and cellular plasticity.

METHODS

We treated nontumorigenic mammary epithelial cells, MCF10A, with 21 chemicals at four concentrations (25  nM , 250  nM , 2.5 μ M , and 25 μ M ) for 48 h. We conducted RNA-sequencing for these 408 samples, adapting the plexWell plate-based RNA-sequencing method to analyze differences in gene expression. We calculated gene and biological pathway-specific benchmark concentrations (BMCs) using BMDExpress3, identifying differentially expressed genes and generating the best fit benchmark concentration models for each chemical across all genes. We identified enriched biological processes and pathways for each chemical and tested whether chemical exposures change predicted cell type distributions. We contextualized benchmark concentrations relative to human population biomarker concentrations in NHANES.

RESULTS

We detected chemical concentration-dependent differences in gene expression for thousands of genes. Enrichment and cell type distribution analyses showed benchmark concentration responses correlated with differences in breast cancer-related pathways, including induction of basal-like characteristics for some chemicals, including arsenic, lead, copper, and methyl paraben. Comparison of benchmark data to NHANES chemical biomarker (urine or blood) concentrations indicated an overlap between exposure levels and levels sufficient to cause a gene expression response.

DISCUSSION

These analyses revealed that many of these 21 chemicals resulted in differences in genes and pathways involved in breast cancer in vitro at human exposure-relevant concentrations. https://doi.org/10.1289/EHP12886.

The Role of the Toll-like Receptor 2 and the cGAS-STING Pathways in Breast Cancer: Friends or Foes?

Breast cancer stands as a primary malignancy among women, ranking second in global cancer-related deaths. Despite treatment advancements, many patients progress to metastatic stages, posing a significant therapeutic challenge. Current therapies primarily target cancer cells, overlooking their intricate interactions with the tumor microenvironment (TME) that fuel progression and treatment resistance. Dysregulated innate immunity in breast cancer triggers chronic inflammation, fostering cancer development and therapy resistance. Innate immune pattern recognition receptors (PRRs) have emerged as crucial regulators of the immune response as well as of several immune-mediated or cancer cell-intrinsic mechanisms that either inhibit or promote tumor progression. In particular, several studies showed that the Toll-like receptor 2 (TLR2) and the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathways play a central role in breast cancer progression. In this review, we present a comprehensive overview of the role of TLR2 and STING in breast cancer, and we explore the potential to target these PRRs for drug development. This information will significantly impact the scientific discussion on the use of PRR agonists or inhibitors in cancer therapy, opening up new and promising avenues for breast cancer treatment.

p53 deficient breast cancer cells reprogram preadipocytes toward tumor-protective immunomodulatory cells

The TP53 gene is mutated in approximately 30% of all breast cancer cases. Adipocytes and preadipocytes, which constitute a substantial fraction of the stroma of normal mammary tissue and breast tumors, undergo transcriptional, metabolic, and phenotypic reprogramming during breast cancer development and play an important role in tumor progression. We report here that p53 loss in breast cancer cells facilitates the reprogramming of preadipocytes, inducing them to acquire a unique transcriptional and metabolic program that combines impaired adipocytic differentiation with augmented cytokine expression. This, in turn, promotes the establishment of an inflammatory tumor microenvironment, including increased abundance of Ly6C+ and Ly6G+ myeloid cells and elevated expression of the immune checkpoint ligand PD-L1. We also describe a potential gain-of-function effect of common p53 missense mutations on the inflammatory reprogramming of preadipocytes. Altogether, our study implicates p53 deregulation in breast cancer cells as a driver of tumor-supportive adipose tissue reprogramming, expanding the network of non-cell autonomous mechanisms whereby p53 dysfunction may promote cancer. Further elucidation of the interplay between p53 and adipocytes within the tumor microenvironment may suggest effective therapeutic targets for the treatment of breast cancer patients.

Global transcriptomic analysis of breast cancer and normal mammary epithelial cells infected with Borrelia burgdorferi

The bacterial spirochete Borrelia burgdorferi, the causative agent of Lyme Disease, can disseminate and colonize various tissues and organs, orchestrating severe clinical symptoms including arthritis, carditis, and neuroborreliosis. Previous research has demonstrated that breast cancer tissues could provide an ideal habitat for diverse populations of bacteria, including B. burgdorferi, which is associated with a poor prognosis. Recently, we demonstrated that infection with B. burgdorferi enhances the invasion and migration of triple-negative MDA-MB-231 cells which represent a type of breast tumor with more aggressive cancer traits. In this study, we hypothesized that infection by B. burgdorferi affects the expression of cancer-associated genes to effectuate breast cancer phenotypes. We applied the high-throughput technique of RNA-sequencing on B. burgdorferi-infected MDA-MB-231 breast cancer and normal-like MCF10A cells to determine the most differentially expressed genes (DEG) upon infection. Overall, 142 DEGs were identified between uninfected and infected samples in MDA-MB-231 while 95 DEGs were found in MCF10A cells. A major trend of the upregulation of C-X-C and C-C motif chemokine family members as well as genes and pathways was associated with infection, inflammation, and cancer. These genes could serve as potential biomarkers for pathogen-related tumorigenesis and cancer progression which could lead to new therapeutic opportunities.

Pancreatic Cancer-Secreted Proteins: Targeting Their Functions in Tumor Microenvironment

Pancreatic Ductal Adenocarcinoma (PDAC) is a ravaging disease with a poor prognosis, requiring a more detailed understanding of its biology to foster the development of effective therapies. The unsatisfactory results of treatments targeting cell proliferation and its related mechanisms suggest a shift in focus towards the inflammatory tumor microenvironment (TME). Here, we discuss the role of cancer-secreted proteins in the complex TME tumor-stroma crosstalk, shedding lights on druggable molecular targets for the development of innovative, safer and more efficient therapeutic strategies.

Collagen-Anchored Interleukin-2 and Interleukin-12 Safely Reprogram the Tumor Microenvironment in Canine Soft-Tissue Sarcomas

PURPOSE

Cytokine therapies such as IL2 and IL12 suffer from impractically small therapeutic windows driven by their on-target, off-tumor activity, limiting their clinical potential despite potent antitumor effects. We previously engineered cytokines that bind and anchor to tumor collagen following intratumoral injection, and sought to test their safety and biomarker activity in spontaneous canine soft-tissue sarcomas (STS).

EXPERIMENTAL DESIGN

Collagen-binding cytokines were canine-ized to minimize immunogenicity and were used in a rapid dose-escalation study in healthy beagles to identify a maximum tolerated dose. Ten client-owned pet dogs with STS were then enrolled into trial, receiving cytokines at different intervals prior to surgical tumor excision. Tumor tissue was analyzed through IHC and NanoString RNA profiling for dynamic changes within treated tumors. Archived, untreated STS samples were analyzed in parallel as controls.

RESULTS

Intratumorally administered collagen-binding IL2 and IL12 were well tolerated by STS-bearing dogs, with only Grade 1/2 adverse events observed (mild fever, thrombocytopenia, neutropenia). IHC revealed enhanced T-cell infiltrates, corroborated by an enhancement in gene expression associated with cytotoxic immune function. We found concordant increases in expression of counter-regulatory genes that we hypothesize would contribute to a transient antitumor effect, and confirmed in mouse models that combination therapy to inhibit this counter-regulation can improve responses to cytokine therapy.

CONCLUSIONS

These results support the safety and activity of intratumorally delivered, collagen-anchoring cytokines for inflammatory polarization of the canine STS tumor microenvironment. We are further evaluating the efficacy of this approach in additional canine cancers, including oral malignant melanoma.

Acute-serum amyloid A and A-SAA-derived peptides as formyl peptide receptor (FPR) 2 ligands

Originally, it was thought that a single serum amyloid A (SAA) protein was involved in amyloid A amyloidosis, but in fact, SAA represents a four-membered family wherein SAA1 and SAA2 are acute phase proteins (A-SAA). SAA is highly conserved throughout evolution within a wide range of animal species suggestive of an important biological function. In fact, A-SAA has been linked to a number of divergent biological activities wherein a number of these functions are mediated via the G protein-coupled receptor (GPCR), formyl peptide receptor (FPR) 2. For instance, through the activation of FPR2, A-SAA has been described to regulate leukocyte activation, atherosclerosis, pathogen recognition, bone formation and cell survival. Moreover, A-SAA is subject to post-translational modification, primarily through proteolytic processing, generating a range of A-SAA-derived peptides. Although very little is known regarding the biological effect of A-SAA-derived peptides, they have been shown to promote neutrophil and monocyte migration through FPR2 activation via synergy with other GPCR ligands namely, the chemokines CXCL8 and CCL3, respectively. Within this review, we provide a detailed analysis of the FPR2-mediated functions of A-SAA. Moreover, we discuss the potential role of A-SAA-derived peptides as allosteric modulators of FPR2.

Diverse Neutrophil Functions in Cancer and Promising Neutrophil-Based Cancer Therapies

Neutrophils represent the most abundant cell type of leukocytes in the human blood and have been considered a vital player in the innate immune system and the first line of defense against invading pathogens. Recently, several studies showed that neutrophils play an active role in the immune response during cancer development. They exhibited both pro-oncogenic and anti-tumor activities under the influence of various mediators in the tumor microenvironment. Neutrophils can be divided into several subpopulations, thus contradicting the traditional concept of neutrophils as a homogeneous population with a specific function in the innate immunity and opening new horizons for cancer therapy. Despite the promising achievements in this field, a full understanding of tumor-neutrophil interplay is currently lacking. In this review, we try to summarize the current view on neutrophil heterogeneity in cancer, discuss the different communication pathways between tumors and neutrophils, and focus on the implementation of these new findings to develop promising neutrophil-based cancer therapies.